The invention concerns an integrated modular tool for pipe end preparation and end-to-end welding of pipes. The tool can be used under all conditions where fast repair or joining of pipelines is needed. Especially when working under hyperbaric conditions on the seabed, it is essential that the repair can be done in a fast and secure way.
To achieve acceptable mechanized welds it is essential to have the pipe ends prepared and aligned within defined tolerances. When two pipe ends are to be butt welded, the confronting ends of the members will be cut, and normally also beveled, before welding. This involves separate machinery.
In welding of large diameter pipe sections to one another, it is extremely difficult to position and maintain the pipe sections in a proper end-to-end position so that they may properly be welded to one another.
In such operations it is conventional to encircle one section with a clamp with a plurality of jacks which extend beyond the free end of one pipe section and span the joint between the two pipe sections that are to be welded together. The jacks include jack screws which are adjustable radially of the clamp so as to move into engagement with the second pipe section and support one end of the latter in confronting relation with the free end of the pipe section on which the clamp is mounted. The jack screws may be adjusted to align the second pipe section with the first pipe section and, in most cases, the jack screws may be adjusted so as to reform or reshape the configuration of the second pipe to match that of the first pipe.
From GB 2,074,068 there is known an apparatus and method for use in fitting, prior to welding, two pipe sections in end-to-end or telescoping relation. The apparatus includes a fixed support for one of the members to be welded and an annular clamp that is adapted to encircle and clamp the member adjacent its end to which the second member is to be welded. The apparatus also includes a second annular clamp member adapted to encircle the second member that is to be welded to the first member. The two clamp members are spaced apart a distance sufficient to enable the confronting ends of the members to be welded to lie in an exposed position between the two clamp members. Each of the clamp units is provided with a plurality of pressure devices for exerting force on the pipe so as to reform or reshape the pipe ends. The pressure devices have to be operated manually.
The welding is normally done by a welding machine on a separate track. An apparatus of this type is, as an example, described in GB 1,534,773. The apparatus comprises a track capable of being secured to and encircling one of the pipes to be welded at a predetermined distance from an end of the pipe. A movable member is capable of being rapidly coupled to and uncoupled from the track. This member carries an arc welding head and is capable of movement along the track by means of a drivable pinion, which is made to engage teeth on the track.
After welding, control of the weld is required. This involves another operation with testing apparatus on a separate track.
The process of preparing two pipe ends to be welded, the welding, and finally inspection, involves many different operations, and most of the operations also include manual work. Due to the many operation steps and the use of different tools, the whole process will, in addition, be time-consuming. Especially when working under hyperbaric conditions in a habitat with a maximum working depth of 400 msw, it is essential that physical work is avoided and that the work can be finished within a short time.
The main object of the invention is therefore to obtain a tool for faster and easier repair of pipelines.
Another object of the invention is to use the same basic tool for all operations involved, such as round up (reforming a pipe end in a substantially circular configuration), cutting, preparing the pipe end grooves, welding and finally non-destructive testing (NDT).